Diagnostics play a critical role for the detection and prevention of diseases or health-related conditions. Diagnostic tools are used for instance to detect proteins, hormones, pathogens, toxins or metabolites for patients suffering from chronic cardiac diseases, diabetes, infections or allergies, just to name a few. A passive detection scheme is beneficial for routine monitoring as they do not require the patient, doctor or other healthcare provider to actively collect and analyze samples.
Optical analysis is a convenient approach to analyzing fluid samples, where color change is used to signify the presence of various indicators in the sample. However, the reagents typically used for analysis require a particular dwell time for reaction with the sample before the sample can be read. Further, the dwell time varies for different reagents. Thus, employing a passive detection scheme for optical analysis with different reagents is challenging.
Therefore, techniques for optical analysis which enable monitoring a continuous flow of a fluid sample would be desirable.